The invention relates to an X-ray unit with a table top and a supporting frame. The frame is supported so as to move in the longitudinal direction by a guide which is mounted on a pedestal. The guide is mounted on the pedestal so as to swivel about a horizontal swivel axis. A swivel motion of the guide can be converted by a lever arrangement and a connecting rod into a longitudinal movement of the table top.
Such a unit can be swivelled into a position in which the table top is vertical (a low foot position), and can be swivelled out of this position through the horizontal position into a so-called low head position. Because the swivel axis must be relatively low, it is necessary, when swivelling the table top, to move the frame within the guide in the longitudinal direction of the table in such a way that the table does not collide with the floor in the two extreme swivel positions.
An X-ray unit of the type described above is described in DE-PS No. 970 321. The frame is moved in this unit by a connecting rod coupled to a lever arrangement. As a result, the swivel motion of the guide produces a longitudinal movement of the table supporting frame. The lever arrangement in the known unit is, of course, only effective when the frame is swivelled through the horizontal position into the low head position. In this case, a cam mounted on the guide acts on the lever arrangement. The activation of the lever arrangement by the cam is sudden, resulting in shaking of the unit. If the unit is swivelled through the horizontal position in the direction of the foot end, the cam no longer acts on the lever arrangment, and the frame can be moved freely in the direction of the head end (i.e. its position is then independent of the swivel position of the unit).